We have used tree layout.
We have created each box with following command -
Box childNode = fc.CreateBox(0, 0, 80, 50);

We have used the arrows pointing from child node to parent node, for this we have used reversedArrows option in the constructor of tree layout as true. When we link the arrow with parentnode as source and child node as destination -

Arrow link = fc.CreateArrow(parentnode, childNode);

Now when we call -
treeLayout.Arrange(fc);

the tree layout doesnt work, all the boxes are placed in the position where they were created i.e (0,0)

Now if we change the link as
Arrow link = fc.CreateArrow(childNode,parentnode);

then the tree is drawn correctly but the expanding happens in opposite direction, i.e when we click on expand button of any node, then its parent is expanded or collapsed.

We want the arrows pointing from childnode to parentnode, but the expanding to happen the normal way, i.e when clicked on expand button of any node, then its child should be expanded or collapsed. Please explain this.

This works fine, thanks.
But if a childnode has two parents, and if one of the parent is collapsed, then the child node should not collapse, only the link should go.
Now the child node is getting collapsed if any of the parent is collapsed.
How to do this?